OSM Ausschnitte herunterladen

<www.openstreetmap.org/export>

osm export

osm export

Das R-Paket XML - Gaston Sanchez

library("XML")

Gaston Sanchez - Dataflow

Seine Arbeit sieht man hier.

Das Arbeiten mit XML Daten

Gaston Sanchez - Webdaten bekommen

Gaston Sanchez - Webdaten bekommen

Funktionen im XML Paket

Function Description
xmlName() name of the node
xmlSize() number of subnodes
xmlAttrs() named character vector of all attributes
xmlGetAttr() value of a single attribute
xmlValue() contents of a leaf node
xmlParent() name of parent node
xmlAncestors() name of ancestor nodes
getSibling() siblings to the right or to the left
xmlNamespace() the namespace (if there’s one)

Einzelne Objekte finden

<www.openstreetmap.org/export>

osm export

osm export

Beispiel: administrative Grenzen Berlin

Administrative Grenzen für Deutschland

url <- "https://api.openstreetmap.org/api/0.6/relation/62422"
BE <- xmlParse(url)
BE <- xmlParse("../data/62422.xml")
Administrative Grenzen Berlin

Administrative Grenzen Berlin

Das XML analysieren

xmltop = xmlRoot(BE)
class(xmltop)
## [1] "XMLInternalElementNode" "XMLInternalNode"       
## [3] "XMLAbstractNode"
xmlSize(xmltop)
## [1] 1
xmlSize(xmltop[[1]])
## [1] 337

Nutzung von Xpath

Xpath, the XML Path Language, is a query language for selecting nodes from an XML document.

xpathApply(BE,"//tag[@k = 'population']")
## [[1]]
## <tag k="population" v="3440441"/> 
## 
## attr(,"class")
## [1] "XMLNodeSet"

Quelle für die Bevölkerungsgröße

xpathApply(BE,"//tag[@k = 'source:population']")
## [[1]]
## <tag k="source:population" v="http://www.statistik-berlin-brandenburg.de/Publikationen/Stat_Berichte/2010/SB_A1-1_A2-4_q01-10_BE.pdf 2010-10-01"/> 
## 
## attr(,"class")
## [1] "XMLNodeSet"

-Statistik Berlin Brandenburg

Etwas überraschend:

xpathApply(BE,"//tag[@k = 'name:ta']")
## [[1]]
## <tag k="name:ta" v="<U+0BAA><U+0BC6><U+0BB0><U+0BCD><U+0BB2><U+0BBF><U+0BA9><U+0BCD>"/> 
## 
## attr(,"class")
## [1] "XMLNodeSet"

Geographische Region

region <- xpathApply(BE,
  "//tag[@k = 'geographical_region']")
# regular expressions
region[[1]]
## <tag k="geographical_region" v="Barnim;Berliner Urstromtal;Teltow;Nauener Platte"/>
<tag k="geographical_region" 
  v="Barnim;Berliner Urstromtal;
  Teltow;Nauener Platte"/>

Landkreis

Barnim

Barnim

Weiteres Beispiel

url2<-"http://api.openstreetmap.org/api/0.6/node/25113879"
obj2<-xmlParse(url2)
obj_amenity<-xpathApply(obj2,"//tag[@k = 'amenity']")[[1]]
obj_amenity
## <tag k="amenity" v="university"/>

Wikipedia Artikel

xpathApply(obj2,"//tag[@k = 'wikipedia']")[[1]]
## <tag k="wikipedia" v="de:Universität Mannheim"/>
xpathApply(obj2,"//tag[@k = 'wheelchair']")[[1]]
xpathApply(obj2,"//tag[@k = 'name']")[[1]]

Das C und das A

url3<-"http://api.openstreetmap.org/api/0.6/node/303550876"
obj3 <- xmlParse(url3)
xpathApply(obj3,"//tag[@k = 'opening_hours']")[[1]]
## <tag k="opening_hours" v="Mo-Sa 09:00-20:00; Su,PH off"/>

Hin und weg

url4<-"http://api.openstreetmap.org/api/0.6/node/25439439"
obj4 <- xmlParse(url4)
xpathApply(obj4,"//tag[@k = 'railway:station_category']")[[1]]
## <tag k="railway:station_category" v="2"/>

Exkurs: Bahnhofskategorien

library(rvest)
## Loading required package: xml2
## 
## Attaching package: 'rvest'
## The following object is masked from 'package:XML':
## 
##     xml
bhfkat<-read_html(
  "https://de.wikipedia.org/wiki/Bahnhofskategorie")
df_html_bhfkat<-html_table(
  html_nodes(bhfkat, "table")[[2]],fill = TRUE)

Bahnhofskategorien Übersicht

Stufe Bahnsteigkanten Bahnsteiglänge[Anm 1] Reisende/Tag Zughalte/Tag Service[Anm 2] Stufenfreiheit[Anm 3]
(0) — — — — Nein Nein
1 01 > 000 bis 090 m 00.000 bis 00.049 000 bis 0010 Ja Ja
2 02 > 090 bis 140 m 00.050 bis 00.299 011 bis 0050 — —
3 03 bis 04 > 140 bis 170 m 00.300 bis 0.0999 051 bis 0100 — —
4 05 bis 09 > 170 bis 210 m 01.000 bis 09.999 101 bis 0500 — —
5 10 bis 14 > 210 bis 280 m 10.000 bis 49.999 501 bis 1000 — —
6 00i ab 15 > 280 m bis 000 000000 ab 50.000 000i ab 1001 — —
Gewichtung 20 % 20 % 20 % 20 % 15 % 5 %

Nur fliegen ist schöner

url5<-"http://api.openstreetmap.org/api/0.6/way/162149882"
obj5<-xmlParse(url5)
xpathApply(obj5,"//tag[@k = 'name']")[[1]]
## <tag k="name" v="City-Airport Mannheim"/>
xpathApply(obj5,"//tag[@k = 'website']")[[1]]
## <tag k="website" v="http://www.flugplatz-mannheim.de/"/>
xpathApply(obj5,"//tag[@k = 'iata']")[[1]]
## <tag k="iata" v="MHG"/>

Mehr Beispiele, wie man mit XML Daten umgeht:

Referenzen

citation("XML")
## 
## To cite package 'XML' in publications use:
## 
##   Duncan Temple Lang and the CRAN Team (2018). XML: Tools for
##   Parsing and Generating XML Within R and S-Plus. R package
##   version 3.98-1.11. https://CRAN.R-project.org/package=XML
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {XML: Tools for Parsing and Generating XML Within R and S-Plus},
##     author = {Duncan Temple Lang and the CRAN Team},
##     year = {2018},
##     note = {R package version 3.98-1.11},
##     url = {https://CRAN.R-project.org/package=XML},
##   }
## 
## ATTENTION: This citation information has been auto-generated from
## the package DESCRIPTION file and may need manual editing, see
## 'help("citation")'.

Das neuere Paket

citation("xml2")
## 
## To cite package 'xml2' in publications use:
## 
##   Hadley Wickham, James Hester and Jeroen Ooms (2018). xml2: Parse
##   XML. R package version 1.2.0.
##   https://CRAN.R-project.org/package=xml2
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {xml2: Parse XML},
##     author = {Hadley Wickham and James Hester and Jeroen Ooms},
##     year = {2018},
##     note = {R package version 1.2.0},
##     url = {https://CRAN.R-project.org/package=xml2},
##   }